Message-ID: <61ebdd1a-2737-0516-08fd-3b9aa0ddd4fe@collabora.com>
Date:   Fri, 24 Feb 2023 14:08:27 +0100
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Subject: Re: [PATCH v3 08/11] drm/panfrost: Add the MT8192 GPU ID
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To:     Chen-Yu Tsai <wenst@chromium.org>,
        Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>,
        Steven Price <steven.price@arm.com>
Cc:     airlied@gmail.com, daniel@ffwll.ch, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, matthias.bgg@gmail.com,
        robh@kernel.org, dri-devel@lists.freedesktop.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org
References: <20230223133440.80941-1-angelogioacchino.delregno@collabora.com>
 <20230223133440.80941-9-angelogioacchino.delregno@collabora.com>
 <CAGXv+5Hzin_5aTqMRRztWbDR64z6_oFOx2hUVnpJBvk9xDzrfw@mail.gmail.com>
From:   AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>
In-Reply-To: <CAGXv+5Hzin_5aTqMRRztWbDR64z6_oFOx2hUVnpJBvk9xDzrfw@mail.gmail.com>
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Il 24/02/23 11:06, Chen-Yu Tsai ha scritto:
> On Thu, Feb 23, 2023 at 9:35 PM AngeloGioacchino Del Regno
> <angelogioacchino.delregno@collabora.com> wrote:
>>
>> From: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
>>
>> MediaTek MT8192 has a Mali-G57 with a special GPU ID. Add its GPU ID,
>> but treat it as otherwise identical to a standard Mali-G57.
>>
>> We do _not_ fix up the GPU ID here -- userspace needs to be aware of the
>> special GPU ID, in case we find functional differences between
>> MediaTek's implementation and the standard Mali-G57 down the line.
>>
>> Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
>> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
>> Reviewed-by: Steven Price <steven.price@arm.com>
> 
> Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
> 
> As previously mentioned, MT8195 Mali G57 has minor revision number 1.
> Do we need to handle that?
> 

Maybe something went wrong while sending the reply to the same question on v2?

Anyway, from what I can see on my MT8195 machine, it works fine without adding
any particular handling...

Alyssa, Steven,
are you aware of anything that we should consider?

Regards,
Angelo

>> ---
>>   drivers/gpu/drm/panfrost/panfrost_gpu.c | 8 ++++++++
>>   1 file changed, 8 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/panfrost/panfrost_gpu.c b/drivers/gpu/drm/panfrost/panfrost_gpu.c
>> index 6452e4e900dd..d28b99732dde 100644
>> --- a/drivers/gpu/drm/panfrost/panfrost_gpu.c
>> +++ b/drivers/gpu/drm/panfrost/panfrost_gpu.c
>> @@ -204,6 +204,14 @@ static const struct panfrost_model gpu_models[] = {
>>
>>          GPU_MODEL(g57, 0x9001,
>>                  GPU_REV(g57, 0, 0)),
>> +
>> +       /* MediaTek MT8192 has a Mali-G57 with a different GPU ID from the
>> +        * standard. Arm's driver does not appear to handle this model.
>> +        * ChromeOS has a hack downstream for it. Treat it as equivalent to
>> +        * standard Mali-G57 for now.
>> +        */
>> +       GPU_MODEL(g57, 0x9003,
>> +               GPU_REV(g57, 0, 0)),
>>   };
>>
>>   static void panfrost_gpu_init_features(struct panfrost_device *pfdev)
>> --
>> 2.39.2
>>